Electric paint remover



Sept. 12, 1933. F M, WATSON 1,926,075

ELECTRIC PAINT REMOVER Filed Feb. 19, 1932 if iill" K Watson.

INVENTOR lli/l l////,'///// l// e, 15 ATTORNEY Patented Sept. 12, 1933 UNITED STATES PATENT OFFICE 6 Claims.

(Cl. B19-29) (Granted under the act of March 3, 1883, as amended April 30, 1928; 370 O. G. 757) This invention relates to improvements in an electric paint remover and has for its object to provide a simple, relatively inexpensive, light, durable and eflicient portable device which is electrically heated to such a degree that when moved closely over painted, enameled or Varnished surfaces, the iinish adhering to the surfaces will be quickly so heated that it can be readily and cleanly scraped therefrom.

The invention consists in the novel construction, arrangement and combination of the parts hereinafter more fully set forth in the speciiication and pointed out in the appended claims.

In the accompanying drawing, Fig. l is a top plan View of a device embodying my invention with portions thereof broken away to more clearly illustrate the details of construction;

Fig. 2 is a central, vertical, longitudinal, sectional view of Fig. 1;

Fig. 3 is an enlarged sectional view substantially on line 3-3 of Fig. 2, and with portions oi' the width broken away;

Fig. 4 is an enlarged detail of construction showing in crosssection the securement of each of the oids of heating Wire in their proper positions;

Fig. 5 is a sectional viewof a portion of the handle and one of its supporting columns.

In the accompanying drawing forming a part of this specification and in which like reference characters designate the same parts, 1 represc .ts a metallic cup-shaped frame whose open mouth is of a shape adapted to most e'diciently get at all surfaces from which the finish is desired to be removed.

This shape I have found to be substantially as shown in Fig. l, in which one of the sides is straight while the other two sides meet at a point intermediate the length of the straight side with one of such sides being curved and the other being partly curved and partly straight.

Within and fitting against the bottom of the cup 1 are a plurality of relatively thick asbestos cut or molded sheets 2. Upon the top surface of the upper sheet 2 is a sheet 3 of mica or other insulating material substantially filling the area of the cup 1 and having disposed upon and substantially covering its upper surface a plurality of folds of electrical resistance heating wire 4, the folds being spaced apart from each other and secured to the sheet 3 at a plurality of points through each parallel length of the wire by a plurality of individual Wires 5, Fig. 4, extending around the wire 4 and passing through holes in the sheet 3 and twisted or otherwise individually secured upon the under surface of the sheet 3. This holds the separated wires for forming the heating unit in nxed relation upon the top sur- .face of the sheet 3 so that they cannot be disarranged by rough handling even while the wire 4 is weakened by being electrically heated to incandescence when furnishing the heat necessary to remove the paint or like finish from surfaces.

Upon the top of the sheet 3 and extending around the inner edge of the cup 1 is a relatively narrow strip 6 of mica or other high resistance material.

Extending around the inner edge of the cup l is an angular strip, preferably of metal, 7 whose lower surface impinges against the upper suri'ace of the strips o' and holds the same, together with the sheets 1 and 2, rmly in the bottom of the cup 1. The vertical sides of the strips 7 are removably secured by bolts 8 or otherwise to the side walls of the cup l whose rim 9 is thickened to enable the metal forming the cup l to be thin and light to facilitate its being held in operative position for protracted periods of time without substantial fatigue of the operator and yet strong enough to resist deformation 8 through the usual rough handling to which this class of devices is subjected in commercial use.

The depth of the cup l is such that the heating wire element 4 may be disposed at such depth within the cup 1 as will afford in the protected open area of cup l, when held against the surface whose finish is to be removed, such heat as will in said enclosed area most readily and eiiciently heat the iinish to that degree where it may be readily and cleanly removed from the surface by the simple operation of running over the same with the usual scraper, not shown.

The heating element 4 is formed of bare wires in the sense that they are uri-insulated except by the sheet 3 upon which they are secured, but the opposite ends of the wire 4 projecting beyond the edge of sheet 3 are connected to insulated wire portions l0, 11, (Figs. 1 and 2) which extend in the instance shown along the straight edge and toward the center of sheet 3 where they pass through openings in the straight side of cup l. The bare ends of wires 10, 11 are attached respectively to separated binding posts 12, insulated from each other and from cup l, to which are secured the bare ends of feed wires 13 of cable 14 extending through an opening in the lower side of housing l5 secured to and projecting from the outer surface of the straight side of cup 1 and over the posts 13. Cable 14 is secured to the handle standard 22, 23 by a bolt 24 and clip 25, Fig. 2, to remove strains in manip" ulation from posts 12, while the remaining end is adapted to lead through a convenient pull socket to a source of electric supply.

When the bottom of cup l is a thin light metal, I provide a reinforcing metal strip 16 across that portion thereof to whl h the handle standards are secured and which, with one end of angular portions 17, is secured screws 16a or otherwise to the bottom of cup l. The remaining ends of portions 17 are secured to the upper ends of standards 22 between whose lower ends is secured by bolt 20 a handle 21 of wood or other insulating material.

When the hand of the Voperator is shielded from the heat of the bottom of cup 1, I have found that its operators remove more finish therewith. Accordingly, I have covered this bottom with a sheet of asbestos 25 or other light insulating material. In furtherance of said shielding I have covered the inner and lateral surfaces of the standards 22 each with a like coating 23 (Figs. 2 and 3) of insulating material which are held in position by bolts 18, 20 and 24. The sheet 26 is provided with openings through which the standards 22 are passed before the handle member 2l and bolt 2o are attached thereto, and which sheet 2S is retained in position by a relatively thin strip 27 passing across the top and opposite edges of sheet 26 near its opposite ends, as well as outside the standards 22, 23. This also avoids the direct radiation of heat of strips 27 to the hand of the operator while grasping handle 21. Strips 27 pass upward in contact with the lateral edges of sheet 26 and with the sides of cup l to which the opposite ends of strips 27 are secured by screws 23. The sheet of asbestos 2o' is flaky and impinges on metal throughout its area. This characteristic, and its exposed position, renders said sheet liable to deterioration from abrasion and to ready fracture when held in place by pressure upon a relatively small interior area. In order to provide for its ready replacement and avoid its said fracture liability I have provided said strips 27 holding sheet 26 by relatively broad areas of contact therewith across the top and on opposite edges of sheet 26. l

The curved surface 7 of cup 1 extending from the heel to the point of my device, as shown by the upper side of 1, is adapted to fit close into the corners formed by a plane level surface and a vertical slowly curving surface, while the lower right, smaller circular surface shown in Fig. 1 facilitates the same operation when the vertical surface is sharply curving. The left and lower left straight surfaces, shown in Fig. 1, are adapted for operation on relatively straight surfaces.

It will thus be apparent to those skilled in this art that my invention provides an inexpensive, durable and light finish remover which may be manipulated by one hand, while the usual scraper is used by the other hand, throughout protracted periods of time without substantial fatigue and which is highly efficient even when subjected to the usual rough handling of such more cumbersome and less eflicient devices.

The heating element, formed in the instance shown, of sheet 3 with the heating wire 4 secured thereto by wires 5, Fig. Il, is held from longitudinal movement by the straight edge of sheet 3 contacting with the insulated wires 10 and 11, Fig. 2, and the heads of binding screws l2, Fig. 1. This holding is furthered by the strips 7 clamping the strips 6 against the edges of sheet 3 to firmly hold sheet 3 against the adjacent surface of asbestos sheet 2.

The invention described herein may be manufactured and use: by or for the Government of the United States for governmental purposes without the payment of any royalties thereon.

I claim:

l. In an electric paint remover the combination of a thin metal shallow cup whose side walls are at substantially a right angle to its bottom and comprise differently curved and straight contours, iiexible substantially flat, insulating material covering its bottom, a heating element extending horizontally in a single flat plane over and secured at intervals to said insulating material, a thin relatively wide portion extending about and removably secured to the inner surface of the walls of the cup and whose inner edges impinge against and retain in position the insulating material secured to the heating element, means for connecting the heating element to a source of electric energy, a handle secured to and projecting laterally from said cup, the edge of the cup being adapted to contact with the surface whose paint is to be removed, the heating element being at a distance within the edge of the cup, and said contour of the cup walls being adapted to conform to differently shaped corners raised above the painted surface for the complete removal of paint therefrom.

2. The combination of claim one characterized by the heating element consisting of a substantially flat sheet of mica extending over the area within the cup and under the edges of said p0rtion which retain said mica in place and a heating wire extending at spaced intervals back and forth across the substantial length of the upper face of said sheet and secured thereto at intervals by individual loops of securing wire each extending around and securing the heating wire with its ends piercing said sheet on opposite sides of the wire and secured together, and being further characterized by asbestos under said mica and covering the bottom of the cup and by said means consisting of an insulated wire connecting the opposite ends of said heating wire to binding posts insulated from each other and mounted on the side wall of said cup, and adapted to be connected with the feed wires of an electric cable, whereby the relatively long heat-weakened wire and other parts are retained in place against liability of breakage or displacement from the rough handling and operation to which the device is usually subjected. Y

3. The combination of claim one characterized by the cup being of relatively thin metal whose rim is reinforced and having a reinforcing metal strip extending across the length of and impinging against its bottom, standards secured near opposite ends of said reinforcing strip, a handle extending between the ends of and secured at its opposite ends to said standards, and insulating material covering the bottom of the cup and said strip.

4. The combination of claim one characterized by a sheet of insulating material extending over and impinging against the outer surface of the bottom of the cup, and bands extending across the top of the insulating material and whose opposite ends extend across and in engagement with lateral edges of the top insulating material are secured to the side wall of the cup for retaining in position said last-named sheet of insulating material.

5. The combination of claim one characterized by the heating element having insulated electric wires connecting opposite sides and extending across one end of the heating element and lying Within the edges of the cup and in the same plane with the extent of the heating Wire and being connected to insulated terminal means lying in said plane and secured to the side Wall of the cup, a covering for said terminal means, an electric feed cable extending through an opening in said covering and connected to said terminal means, and means for securing said cable to an outer surfaceof an element of the handle.

6. In a paint remover the combination of an open topped cup having one side thereof straight and Whose other sides meet at a point intermediate the length of said straight side, one of said other sides being of a continuous curve and the other one of said sides being formed of a curve of lesser radius than said iirst-named curve and extending from said point and terminating at its end remote from said point in a straight surface extending to and at substantially a right angle from the rst stated straight side, heating means mounted within said cup, a handle attached to said cup, and means for insulating said handle from the heat Within said cup, whereby the variously contoured sides of the cup are adapted to closely conform to the diierently shaped corners projecting from the surface whose paint may thereby be more readily removed from such corners.

FRANK M. WATSON. 

